CN104126278A - Adaptive Generation of Channel Quality Indicator (CQI) Based on Current Communication Scenario - Google Patents

Abstract

Adaptive generation of channel quality indicators based on a current communication scenario. A plurality of sets of channel quality indicator information may be stored for each of a plurality of UE communication scenarios. The information may be usable in generating a channel quality indicator. During operation of the UE, a current communication scenario of the UE may be determined. A first set of channel quality indicator information may be selected based on the determined current communication scenario being experienced by the UE. At least one channel quality indicator may be determined based on the selected first set of channel quality indicator information. Finally, the channel quality indicator may be provided to a base station.

Description

Adaptive Generation of Channel Quality Indicator (CQI) Based on Current Communication Scenario

technical field

This patent application relates to wireless devices, and more particularly to systems and methods for adaptively generating and transmitting channel quality indicators (CQIs) based on the current communication scenario that the wireless device is experiencing.

Description of related technologies

The use of wireless communication systems is rapidly increasing. Further, wireless communication technology has evolved from only voice communication to also include data transmission such as the Internet and multimedia content. Therefore, wireless communication needs to be improved.

In order to provide improved communication between a base station (BS) and a wireless user equipment (UE), the UE may compute various metrics indicative of channel quality for feedback to the base station. Without loss of generality, these measures may be referred to as channel quality indicators (CQI). The base station can use these channel quality indicators to adjust its communication with the UE to provide improved communication with the UE. For example, these CQI metrics can be used by the BS to determine the code rate and modulation scheme to be allocated to each UE. The code rate and modulation scheme can be chosen to not only maximize the throughput to a particular UE, but also improve the overall throughput of the base station's communication area (eg, cell) through scheduling. The use of channel quality indicators thus allows the base station to more fully utilize the state of the wireless channel to improve communication throughput with various wireless user equipments (UEs).

A channel quality indicator (CQI) may indicate the communication quality of a wireless channel. For example, a CQI may be one or more values representative of channel quality measurements for a given channel. In general, a high value CQI indicates a channel with high quality, while a low value CQI indicates a channel with low quality. A UE generates various metrics for a channel based on downlink (DL) signals it receives, and these metrics are used to determine a channel quality indicator for that channel. These metrics may include estimates of spectral efficiency, number of data layers, precoding matrices, etc. in the context of multiple-input and multiple-output (MIMO) antenna systems. The CQI for a channel may be calculated based on other performance metrics, such as the channel's Signal-to-Noise Ratio (SNR), Signal-to-Interference-plus-Noise Ratio (SINR), Signal-to-Noise-plus-Distortion Ratio (SNDR), etc.

The CQI for a given channel will also depend on the transmission (modulation) scheme used by the communication system. For example, a communication system using Code Division Multiple Access (CDMA) may utilize a different CQI than a communication system using Orthogonal Frequency Division Multiplexing (OFDM). In more complex communication systems, such as those utilizing multiple-input multiple-output (MIMO) and space-time coding systems, the CQI used will also depend on the receiver type. Other factors that may be considered when generating CQI are performance impairments such as Doppler shift, channel estimation error, interference, and the like. Therefore, in order to better reflect the real channel conditions, the CQI fed back to the base station may consider various factors, including receiver algorithm, DL channel configuration, MIMO configuration, and Doppler shift of the channel, among others.

The generation of the channel quality indicator by the UE is important in optimizing the use of the communication channel. Therefore, there is a need for improvement in the generation of CQI in wireless communication systems.

Contents of the invention

Embodiments of the invention may relate to systems and methods for adaptively generating a channel quality indicator (CQI) based on the current communication scenario that the UE is experiencing. More specifically, various embodiments may relate to a method of providing an improved channel quality indicator (CQI) reporting process by utilizing a CQI adaptation process.

In one embodiment, for example, the UE may be configured to store multiple sets of communication scenario information for each of multiple UE communication scenarios during an offline process during design. This may involve performing a CQI adaptation method for each of a plurality of UE communication scenarios to determine sets of communication scenario information, where each set of communication scenario information corresponds to one of the UE communication scenarios. Multiple sets of communication scene information may include one or more mapping tables, such as: 1) a first mapping table for mapping signal-to-noise ratio to spectral efficiency (SNR-SE); 2) a second mapping table for Mapping spectral efficiency to channel quality indicator (SE-CQI); and/or 3) a third mapping table for directly mapping signal-to-noise ratio to channel quality indicator (SNR-CQI).

The determined sets of communication scene information are then stored in the UE. Further, the UE is then configured to selectively utilize one of multiple sets of communication scenario information when generating the CQI based on the current communication status of the UE. Therefore, each set of communication scenario information can be used to generate a channel quality indicator for a corresponding communication scenario.

Each set of communication scenario information may be based on a different combination of one or more of receiver type, multiple-input multiple-output (MIMO) scheme, and Doppler shift, among other parameters.

When a wireless user equipment (UE) is in use, the UE may operate as follows. The UE may determine a current communication scenario of the UE during operation of the UE. For example, the UE may determine its receiver type, the MIMO scheme used by the base station, and/or the amount of Doppler shift. The UE may then select the first set of communication scenario information based on the determined current communication scenario of the UE. The first group of communication scene information may be selected from multiple sets of stored communication scene information. The UE may then generate at least one channel quality indicator based on the selected first set of communication scenario information. Once the channel quality indicator is generated, the UE may then send the channel quality indicator to the base station.

Description of drawings

A better understanding of the invention may be gained when considering the following detailed description of the embodiments in conjunction with the accompanying drawings.

Figure 1A shows an exemplary (and simplified) wireless communication system;

FIG. 1B shows a base station 102 in communication with user equipment 106;

Figure 2 shows an exemplary block diagram of a UE 106 according to one embodiment;

FIG. 3 shows an offline process of generating a mapping table for different possible communication scenarios according to an embodiment of the present invention;

FIG. 4 shows an online process for generating a channel quality indicator based on a current communication scenario according to an embodiment of the present invention;

FIG. 5 shows a CQI adaptive method that can be executed for different communication scenarios according to an embodiment of the present invention;

FIG. 6 shows an example table for modulation and coding schemes in the CQI adaptive method of FIG. 5 according to an embodiment of the present invention;

FIG. 7 shows an exemplary method of CQI calculation using a mapping table determined based on a current communication scene according to an embodiment of the present invention; and

FIG. 8 shows an example table of CQI values according to one embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, certain embodiments of the invention are shown by way of example in the drawings and described in detail herein. It should be understood, however, that the drawings and specific description of the invention are not intended to limit the invention to the particular form disclosed; on the contrary, the invention covers matters within the spirit and scope of the invention as defined by the appended claims. All variations, equivalents and substitutions.

Detailed ways

Acronym

The following abbreviations are used in this provisional patent application:

BLER: block error rate (equivalent to packet error rate)

BER: bit error rate

CRC: Cyclic Redundancy Check

DL: downlink

PER: packet error rate

SINR: Signal to Interference plus Noise Ratio

SIR: Signal to Interference Ratio

SNR: Signal to Noise Ratio

Tx: transmit

UE: user equipment

UL: uplink

UMTS: Universal Mobile Telecommunications System

the term

The following terms are used in this application:

memory medium - any of various memory devices or storage devices. The term "storage medium" is intended to include installation media, such as CD-ROM, floppy disk 104, or tape devices; computer system memory or random access memory, such as DRAM, DDR RAM, SRAM, EDORAM, Rambus RAM, etc.; non-volatile memory , such as flash memory, magnetic media such as hard disks or optical storage devices; registers, or other similar types of memory elements, etc. The storage medium may also include other types of memory or combinations thereof. Furthermore, the storage medium may be located in a first computer that executes the program, or may be located in a different second computer connected to the first computer through a network such as the Internet. In the latter case, the second computer may provide the first computer with program instructions for execution. The term "storage medium" may include two or more storage media that may reside in different computers in different locations, eg connected by a network.

Carrier Medium - a memory medium as described above, and a physical transmission medium such as a bus, network and/or other physical transmission medium that conveys signals such as electrical, electromagnetic or digital signals.

Programmable Hardware Element - includes various hardware devices including a number of programmable functional blocks connected via programmable interconnects. Examples include FPGAs (Field Programmable Gate Arrays), PLDs (Programmable Logic Devices), FPOA (Field Programmable Object Arrays), and CPLDs (Complex Programmable Logic Devices). Programmable function blocks can range from fine-grained (combinational logic or look-up tables) to coarse-grained (arithmetic logic units or processor cores). Programmable hardware elements may also be referred to as "configurable logic."

Computer System – any of various types of computing or processing systems, including personal computer systems (PCs), mainframe computer systems, workstations, network appliances, Internet appliances, personal digital assistants (PDAs), television systems, grid computing A system or other device or combination of devices. In general, the term "computer system" may be broadly defined to include any device (or combination of devices) having at least one processor that executes instructions from a memory medium.

User Equipment (UE) (or "UE Device") - any of various types of computer system devices that are mobile or portable and that perform wireless communications. Examples of UE devices include mobile or smart phones (e.g. iPhone ^™ , Android ^™ phones), portable gaming devices (e.g. Nintendo DS ^™ , PlayStation Portable ^™ , Gameboy Advance ^™ , iPhone ^™ ), laptops, PDAs, portable Internet devices, music players, data storage devices, or other handheld devices, etc. In general, the term "UE" or "UE device" may be broadly defined to include any electronic, computing, and/or telecommunications device (or combination of devices) that is conveniently transportable by a user and capable of wireless communication.

Automatic – refers to an action or operation performed by a computer system (e.g., software executed by a computer system) or device (e.g., circuitry, programmable hardware components, ASIC, etc.) without requiring user input to directly specify or perform the action or operation . As such, the term "automatic" is in contrast to a manually performed or specified operation by a user, where the user provides input to directly perform the operation. An automated process may be initiated by input provided by a user without subsequent automatically performed actions being specified by the user, ie, rather than being performed manually, where the user specifies each action to perform. For example, by selecting each field and providing input specifying information, a user filling out an electronic form (e.g., by typing information, selecting check boxes, radio boxes, etc.) is manually filling out the form, even though the computer system must update the form in response to user action . Forms can be automatically filled out by a computer system, where the computer system (eg, software executing on the computer system) analyzes the fields of the form and fills in the form without any user inputting answers to the specified fields. As noted above, a user may invoke auto-fill of a form, but not participate in the actual filling of the form (eg, the user does not manually specify answers to fields but they are auto-completed). This manual provides examples of various operations that are automatically performed in response to actions taken by the user.

Figure 1A and 1B – Communication system

Figure 1A shows an exemplary (and simplified) wireless communication system. Note that the system of FIG. 1A is only one example of a possible system, and that various embodiments of the invention may be implemented in any of a variety of systems, as desired.

As shown, an exemplary wireless communication system includes a base station 102 that communicates with one or more user equipment (UE) (or "UE devices") 106A via a transmission medium through 106N.

Base station 102 may be a base transceiver station (BTS) or a cell site, and may include hardware capable of supporting wireless communications with UEs 106A-106N. Base station 102 may also be equipped to communicate with network 100 . As such, base station 102 may facilitate communication between UEs and/or between UEs and network 100 . A communication area (or coverage area) of a base station may be referred to as a "cell." The base station 102 and the UE may be configured to communicate over a transmission medium using any of various wireless communication technologies such as GSM, CDMA, WLL, WAN, WiFi, and WiMAX, among others.

FIG. 1B shows UE 106 (e.g., one of devices 106A through 106N) in communication with base station 102. UE 106 may be a device with wireless network connectivity, such as a mobile phone, handheld device, computer or tablet, or virtually any type of wireless device. UE 106 may include a processor configured to execute program instructions stored in memory. The UE may perform any of the various embodiments described herein by executing such stored instructions. In some embodiments, the UE may include a device such as an FPGA (Field Programmable Gate Array) configured to perform any of the method embodiments described herein, or any of the method embodiments described herein. Part of the programmable hardware element.

In some embodiments, UE 106 may be configured to generate one or more channel quality indicators (CQIs) that are provided back to base station 102. The base station 102 can use these CQIs received from one or more base stations to regulate its communication with the corresponding UE 106 or possibly other UEs 106. For example, in one embodiment, base station 102 can receive and utilize CQIs from multiple UEs 106 to adjust its communication schedule among various UEs within its coverage area (or cell).

User equipment (UE) 106 can use the CQI generation method as described herein to determine the CQI to feed back to the base station (BS). In one embodiment, the generation of the CQI is performed based on the current communication scenario that the UE is experiencing. As described below, during the offline procedure, information (eg, a mapping table) can be generated for possible different communication scenarios and can be stored in the UE. Later, when the UE is actually in use (online), the UE may determine the current communication scenario being experienced and select pre-stored information (eg, a mapping table) for generating a channel quality indicator (CQI).

Figure 2 – An exemplary block diagram of a UE

FIG. 2 shows an exemplary block diagram of UE 106. As shown, UE 106 may include a system on chip (SOC) 200, which may include multiple parts for various purposes. For example, as shown, the SOC 200 may include one or more processors 202 that may execute program instructions for the UE 106 and display circuitry 204 that may perform graphics processing and provide display signals to a display 240. The one or more processors 202 may also be coupled to a memory management unit (MMU) 240, which may be configured to receive addresses from the one or more processors 202 and translate those addresses into memory (e.g., memory 206 , read-only memory (ROM) 250, NAND flash memory 210) and/or other circuits or devices (eg, display circuitry 204, radio 230, connector I/F 220, and/or display 240). MMU 240 may be configured to perform memory protection and page table translation or setup. In some embodiments, MMU 240 may be included as part of one or more processors 202.

In the illustrated embodiment, ROM 250 may include a bootloader 252, which is executable by one or more processors 202 during startup or initialization. As also shown, the SOC 200 may be coupled to various other circuits of the UE 106. For example, UE 106 may include various types of memory (e.g., including NAND flash memory 210), connector interface 220 (e.g., for coupling to a computer system), display 240, and wireless communication that may use antenna 235 to perform wireless communication. Circuitry (eg, for GSM, Bluetooth, WiFi, etc.). As described herein, UE 106 may include hardware and software components for generating CQI values and/or providing CQI values to a base station.

Figure 3 – Offline generation of mapping tables for different communication scenarios

Fig. 3 shows an offline process of generating a mapping table for different possible communication scenarios according to an embodiment of the present invention. The method shown in FIG. 3 may be used in conjunction with, among other devices, any of the computer systems or devices shown in the above figures. In various embodiments, some of the method components shown may be performed concurrently in an order different from that shown, or may be omitted. Additional method components can also be implemented as desired. As shown, the method may operate as follows.

As shown, at 302, a CQI adaptation process may be performed for a plurality of different communication scenarios to generate scenario information for each communication scenario (referred to herein as a "scenario"). The scenario information may be any information used to generate one or more CQIs for that scenario. In one embodiment, scene information may include one or more mapping tables. Multiple sets of communication scene information may include one or more mapping tables, such as: 1) a first mapping table for mapping signal-to-noise ratio to spectral efficiency (SNR-SE); 2) a second mapping table for Mapping spectral efficiency to channel quality indicator (SE-CQI); and/or 3) a third mapping table for directly mapping signal-to-noise ratio to channel quality indicator (SNR-CQI).

Each set of communication scenario information may be based on one or more of receiver type, multiple-input multiple-output (MIMO) scheme, Doppler shift, downlink (DL) channel combination, and radio conditions, among other parameters. different combinations. In some embodiments, context information may be based on various combinations or all of the above factors.

Various receiver types or algorithms may include Linear Minimum Mean Square Error (LMMSE), Maximum Likelihood Method (MLM), and Linear Minimum Mean Square Error with Serial Interference Suppression (LMMSE-SIC), among others.

Additionally, scenarios may correspond to different MIMO schemes or DL channel configurations. Therefore, different MIMO schemes and precoding matrices can be targeted, such as large delay CDD (cyclic delay diversity), closed-loop precoding matrix (to utilize channel capacity), space frequency or time block coding (SFBC or STBC) (to utilize channel diversity) etc. to generate scenario information for determining CQI.

Further, scenarios may take into account different Doppler shifts. Note that Doppler shift can characterize the time-domain fading of a wireless channel. Thus, scene information may incorporate the effects of Doppler shift into receiver performance and factor these effects into one or more maps. Additional scenarios may incorporate wireless channel conditions, among others.

Note that in some communication scenarios such as different MIMO and DL channel configurations, closed-form analysis results may be obtained. In other scenarios, eg for receiver algorithms and channel Doppler effects, a closed-form estimate may not be available. Thus, in some embodiments, a UE may perform a CQI adaptation procedure as described herein to determine an appropriate CQI estimate or adjustment based on empirical data or a calibration process.

Exemplary details for 302 are provided below with reference to FIG. 5 .

In 304, context information (eg, a mapping table) may be stored in one or more UEs. More specifically, the scene information for each scene applicable to each UE may be stored in a memory of the corresponding UE, for example in ROM 250, flash memory 210, or copied to memory 206. In one embodiment, applicable scenarios may be all the scenarios used in 302 . In other words, in this embodiment, all the context information generated in 302 can be stored in each UE. Alternatively, only a subset of the multiple sets of context information may be stored in each UE, depending on the context applicable to the UE. For example, if a UE does not support a particular scenario (eg, if the UE does not have appropriate hardware to support a particular scenario), corresponding scenario information may not be stored in the UE's memory.

Note that although FIG. 3 is described as an offline process (e.g., performed during design or prior to manufacture of the UE), it is possible that this process could alternatively or additionally be performed in-line, e.g. One or more of the scene information is updated to the current state. For example, where a particular scene has been identified, then scene information corresponding to the current scene, rather than optimized or aggregated scene information such as generated at 302 above, may be updated to reflect the particular current state. Thus, the method of FIG. 3 can be augmented or even replaced with a similar in-line process, as desired.

The context information of 304 may be used to determine online information of one or more CQIs, such as described below with reference to FIG. 4 .

Figure 4 – Generation of CQI during UE use

Fig. 4 shows an online process of generating a channel quality indicator based on a current communication scenario according to an embodiment of the present invention. The method shown in FIG. 4 may be used in conjunction with any of the computer systems or devices shown in the above figures, among other devices. In various embodiments, some of the method components shown may be performed concurrently in an order different from that shown, or may be omitted. Additional method components can also be implemented as desired. As shown, the method may operate as follows.

As shown in the figure, in 402, for example, the UE may determine the current scene. For example, determining the current scene may involve determining the current receiver type, MIMO scheme, and/or Doppler shift, among other possibilities. This information may be determined by performing measurements or by accessing current state data (eg stored in local memory or received from another source such as the BS) as desired. For example, the current MIMO scheme may be stored in memory or registers of the UE.

At 404, based on the current context, communication context information may be selected from a memory of the UE 106. More specifically, the scene information corresponding to the current scene may be selected to be used for generating the current one or more CQIs. In one embodiment, as described above, the scene information may include, among other possible parameters, one or more mapping tables corresponding to the current receiver type, MIMO scheme and/or Doppler shift. The scene information can be used to determine the CQI for the current scene that the UE 106 is experiencing.

Accordingly, at 406, one or more CQIs can be generated using the selected 404 communication scenario information. The CQI may be generated based on current quality information and selected communication scene information. The quality information used in generating the CQI may be any of various metrics, such as signal-to-noise ratio (SNR), spectral efficiency (SE), or other quality metrics. For example, based on the current quality information, one or more mapping tables corresponding to the current scenario may be used to determine one or more CQI values to provide to the base station. Figure 7, described in more detail below, provides exemplary details corresponding to this method.

Finally, at 408, the generated one or more CQIs can be provided to the base station. Based on the current quality of the channel indicated by the provided one or more CQIs, the base station can use this information for communicating with the UE in an efficient manner.

Figure 5 – Generation of scenario information for different communication scenarios

Fig. 5 shows a method for generating scenario information of different communication scenarios according to an embodiment of the present invention. The process shown in FIG. 5 is an example of a method that may be performed in 302 of FIG. 3 for different communication scenarios. In this particular embodiment, the scene information is generated as a mapping table, but other embodiments are contemplated. In one embodiment, the method of FIG. 5 is preferably performed offline during the design of the UE to generate information (eg, a mapping table) pre-stored on the UE for later use during operation of the UE 106.

In this exemplary figure, a CQI adaptation procedure may be performed to generate appropriate SNR-SE and SE-CQI mapping tables for later use during operation of the UE. Using different mapping tables for different communication scenarios allows UE 106 to take into account end-to-end receiver performance for CQI reporting and meet BLER target values for each CQI.

Similar to the methods discussed above, the method shown in FIG. 5 may be used in conjunction with any of the computer systems or devices shown in the above figures, among other devices. In various embodiments, some of the method components shown may be performed concurrently in an order different from that shown, or may be omitted. Additional method components can also be implemented as desired. As shown, the method may operate as follows.

At 502, the method can set an initial SNR and an initial MCS for CQI. These values may be set by the UE and/or may be set by another device (eg, test equipment) and provided to the UE receiver. The initial SNR may be set at an initial low level and, as described below, may be increased over time to generate one or more mapping tables. Similarly, MCS may be set at a base level and increased over time to generate one or more mapping tables.

Figure 6 illustrates an exemplary MCS table showing sets of schemes that can be used in the method of Figure 4, although other MCS values and schemes are contemplated. As shown, the MCS table includes an index column, a modulation order column and a total block size index column.

Additionally, at 502, the method (eg, UE receiver) can perform DL demodulation using a selected receiver algorithm (eg, LMMSE, MLM, etc.) for the current fixed SNR with the initial MCS.

In 504, PDSCH decoding can be performed. Additionally, after decoding, the CRC can be checked to see if the transport block was decoded correctly.

At 510, the method measures the PDSCH decoded BLER level to determine whether a BLER target or threshold (shown as "THRESH") is achieved. In some embodiments, an exemplary BLER target value is 10%, although other values may be used. In scenarios such as rapidly varying wireless channels with high Doppler shift, the BLER target value threshold may be as large as 30%, among other possibilities.

If the BLER is determined to be less than or equal to the BLER target value, the MCS may be incremented at 514 and the method may repeat from 502 using the new MCS value.

If the measured BLER is greater than the BLER target value, the method may proceed to 512 .

At 512, the method can obtain a CQI mapped to MCS-1 for use in a mapping table. Additionally, at 506 and 508, the method can calculate the spectral efficiency corresponding to MCS-1 for a given SNR. The method then generates (eg, adds to) a CQI-SE mapping table using the determined CQI and SE in 522 .

Eventually, the SNR can be increased and the method can be repeated for new SNR values until the CQI-SE mapping table is complete.

Figure 7 – Exemplary CQI calculation

Fig. 7 shows an embodiment of a method for generating a channel quality indicator according to an embodiment of the present invention. The method of FIG. 7 can generate a CQI based on the current communication scenario that the UE 106 is experiencing. More specifically, once the current scene (and correspondingly suitable scene information, such as a mapping table) is selected, the method of FIG. 7 can be used. Thus, the method of FIG. 7 can be used in any number of different communication scenarios. In one embodiment, the process shown in FIG. 7 is an example of a method that may be performed in 406 of FIG. 4 . The method of Figure 7 may preferably be performed online, ie during use or operation of the UE.

Also, the method shown in FIG. 7 may be used in conjunction with any of the computer systems or devices shown in the above figures, among other devices. In various embodiments, some of the method components shown may be performed concurrently in an order different from that shown, or may be omitted. Additional method components can also be implemented as desired.

As shown, the method of FIG. 7 may operate as follows.

At 702, MIMO channel estimation and/or noise estimation can be performed. In one embodiment, the channel estimate may be used to generate a whitened channel estimate matrix for CQI calculation.

At 704, an effective SNR estimate for each PMI/RI assumption can be determined. In one embodiment, the SNR estimate may be based on a whitened channel estimate and receiver algorithm (eg, LMMSE, MLM, LMMSE-SIC, among others).

In 706, SNR-to-SE mapping can be performed, for example, using a SNR-to-SE mapping table. As described above, the SNR-SE mapping table can be generated by the adaptive CQI method described in FIGS. 3 and 5 . The SNR-SE mapping table may be selected based on the current communication scenario as described above. The SNR-SE mapping can take into account the channel capacity as well as possible losses due to actual receivers. Note that SE estimation can be done with finer granularity for a small number of resource blocks (eg, two RBs). In one embodiment, the SEs may be further processed, eg, involving averaging over a wide bandwidth, filtering the SEs over time, and the like.

In 708, estimation with optimized PMI/RI (precoding matrix index/ranking index) selection can be performed. PMI/RI may be related to MIMO transmission and may indicate the number of transmission layers in a MIMO scenario. In one embodiment, the UE may use its channel estimate to determine the best PMI & RI and feed back to the eNB for its application at the eNB side. Typically, these values can be calculated together with the CQI, and conceptually they are all part of the channel quality feedback. In the context of LTE, channel quality feedback may report CQI, PMI and RI separately.

In 710, SE to CQI mapping may be performed using, for example, a SE-CQI mapping table to determine the CQI. As described above, the SE-CQI mapping table can be generated by the adaptive CQI method described in FIGS. 3 and 5 . The SE-CQI mapping table may be selected based on the current communication scenario as described above. CQI and/or RI/PMI values may then be reported. Note that CQI may include any of various channel quality feedback indications. For example, the term "CQI" may generally include RI/PMI values and channel quality for the eNB to select a suitable code rate (MCS). Thus, the above discussion of CQI may include one or more values, including RI/PMI values. In this particular example, Channel Quality, RI and PMI values are provided.

Figure 8 provides an exemplary embodiment of a CQI mapping table, for example following the LTE embodiment.

Advantage

Exemplary advantages of the above-described CQI adaptation process include capturing CQI estimation losses that cannot be derived from analysis results, especially for scenarios or algorithms that do not have closed-form analysis results. For example, using MLM methods or simplified MLM methods such as Max-Log-MAP reduction or QR decomposition to separate the bitstream, it is difficult to obtain an accurate estimate of the achievable effective SNR or decoding performance. A CQI adaptation process may be performed to calibrate MLM reception performance and reflect it in a mapping table for CQI calculation, such as a CQI-SE mapping table or a SNR-SE mapping table.

Basic Principles of LTE CQI

As noted above, the embodiments described herein are in the exemplary context of an LTE communication system. More specific implementation details for an exemplary LTE embodiment are provided below.

In LTE, a Channel Quality Indicator (CQI) may be defined as follows. Based on an unrestricted observation interval in time and frequency, the UE derives, for each CQI value reported in uplink subframe n, the highest CQI index in the table of Figure 8 that lies between 1 and 15, or CQI index 0 is deduced if CQI index 1 does not satisfy the condition: the combination with modulation scheme and transport block size corresponding to the CQI index can be received with a transport block error probability not exceeding 0.1 and occupies a set of downlink called CQI reference resources A single Physical Downlink Shared Channel (PDSCH) transport block for each physical resource block.

In LTE, a modulation and coding scheme (MCS) is defined to allow different levels of code rates and modulation orders, such as those in the table of Figure 6 for the DL Physical Downlink Shared Channel (PDSCH). The transport block size (TBS) index is used in the transport block size table defined in the table of FIG. 8 .

Based on the description of the CQI definition for LTE, in one embodiment, it is expected that for any DL configuration given the CQI defined in the table of Fig. 8, the UE achieves a 10% Block Error Rate (BLER) target value. Also, the scheduling algorithm in the BS can be designed according to this exemplary UE needs to improve throughput. Note that what is proposed in the LTE specification is a method of reporting and using CQI for optimizing receiver throughput, which sets a fixed BLER target value for the UE which simplifies optimization at the BS. However, to further improve performance, an adaptive BLER target value can be used based on UE channel conditions and network scenarios. Note that this embodiment involves improving a fixed BLER target value for CQI. However, the methods described herein can be used for various BLER target values for CQI.

other embodiments

Note that in this specification, various embodiments are described in the context of LTE (UTMS Long Term Evolution). Note, however, that the methods described herein can be generalized for CQI reporting using other wireless technologies and are not limited to the specific description provided above.

Embodiments of the invention can be implemented in any of a variety of forms. For example, in some embodiments, the invention can be implemented as a computer-implemented method, a computer-readable storage medium, or a computer system. In other embodiments, the invention may be implemented using one or more custom designed hardware devices, such as ASICs. In other embodiments, the invention may be implemented using one or more programmable hardware components, such as FPGAs.

In some embodiments, a non-transitory computer-readable storage medium may be configured such that it stores program instructions and/or data, wherein the program instructions, if executed by a computer system, cause the computer system to perform a method, such as the methods described herein Any of the embodiments, or any combination of the method embodiments described herein, or any subset of any of the method embodiments described herein, or any combination of such subsets.

In some embodiments, an apparatus (such as a UE) may be configured to include a processor (or group of processors) and a memory medium, wherein the storage medium stores program instructions, wherein the processor is configured to read and Executing the program instructions, wherein the program instructions are executable to implement any of the various method embodiments described herein (or any combination of the method embodiments described herein, or a method implementation described herein any subset of any number of examples, or any combination of these subsets). The device may be implemented in any of various forms.

Although the above embodiments have been described in some detail, various modifications and modifications will become apparent to those skilled in the art once the above disclosure is fully understood. The appended claims are intended to cover all such changes and modifications.

Claims (11)

1. a method of being carried out by wireless user equipment (UE), described method comprises:

In the operating period of UE, determine the current communication scenes of described UE;

Current communication scenes based on determined UE is selected the first group communication scene information, and wherein said the first group communication scene information is selected from the multi-unit message scene information of storage, and wherein every group communication scene information is corresponding to corresponding UE communication scenes;

Based on selected the first group communication scene information, generate at least one CQI; And

Described CQI is sent to base station.

2. method according to claim 1, each group in the multi-unit message scene information wherein stored is one or more based in receiver type, multiple-input and multiple-output (MIMO) scheme and Doppler drift amount all.

3. according to method in any one of the preceding claims wherein, each group in the multi-unit message scene information wherein stored is all based on two or more in receiver type, multiple-input and multiple-output (MIMO) scheme and Doppler drift amount.

4. according to method in any one of the preceding claims wherein,

Each group in the multi-unit message scene information wherein stored is all based on receiver type, multiple-input and multiple-output (MIMO) scheme and Doppler drift amount;

The current communication scenes of wherein said definite UE comprises the MIMO scheme of the receiver type of UE, the use of described base station and the Doppler drift amount that described UE experiences determined.

5. according to method in any one of the preceding claims wherein,

Each group in the multi-unit message scene information wherein stored includes for spectrum efficiency being mapped to one or more mapping tables of described CQI.

6. according to method in any one of the preceding claims wherein,

Each group in the multi-unit message scene information wherein stored includes at least: 1) the first mapping table, and it is for signal to noise ratio is mapped to spectrum efficiency, and 2) the second mapping table, it is for being mapped to spectrum efficiency described CQI.

7. according to method in any one of the preceding claims wherein, described method also comprises:

For each in a plurality of UE communication scenes, carry out CQI adaptive approach to determine described multi-unit message scene information.

8. method according to claim 7, wherein said every in a plurality of UE communication scenes

Carrying out CQI adaptive approach for one comprises:

A) select snr value;

B) based on described signal to noise ratio definition spectral efficiency values;

C) based on described signal to noise ratio, determine modulation and encoding scheme;

D) based on described modulation and encoding scheme and selected snr value generation channel quality indicator values;

Carry out repeatedly a) – d) to generate the mapping table that spectral efficiency values is mapped to channel quality indicator values, wherein said mapping table comprises described communication scenes information.

9. according to method in any one of the preceding claims wherein, described method also comprises:

For each in a plurality of UE communication scenes, store multi-unit message scene information.

10. a subscriber equipment (UE) installs, and described UE device comprises:

Antenna, it is for carrying out the radio communication with base station;

Memory, it is for storing multi-unit message scene information; And

Processor, it is configured to execute claims any in method described in 1-9.

11. 1 kinds of software programs that are configured to execute claims any in method described in 1-9.